Process of treating ores



Patented Dec. 15, 1925.

Y UNITED STATES WILLIAI B. VAN BLYKE, OF EVELE'IE, IIIINESOTA.

PROCESS OI TREATING OBES.

Io Drawing.

To all whom it may concern:

Be it known that I, WILLIAM R. VAN SLYKE, a citizen of the United States, residing at Eveleth, in the county of, St. Louis and State of Minnesota, have invented certain new and useful Improved Processes of Treating Ores, of which the following is a specification.

My invention relates to the treatment of iron ores and more particularly to their preparation for reduction and subsequent I smelting.

It is customary in the reduction of iron ores to use a fuel of sufficient strength to support the burden and having a porous structure to permit and facilitate the passage of reducing gases through thecharge. At present coke and charcoal are the most satisfactory fuels fulfilling these requirements. The development of the iron industry has been substantially confined to areas where coking coal or coke is easily available. In certain districts fuels of a type other than coke' or charcoal, for example, non-coking coals, lignite, eat, charcoal and oil are available and i these can be satisfactorily utilized as the fuel-medium, in addition to the advantages derived therefrom, the development of ore bodies, which are at present unavailable, due either to the grade of the ore body or the absence of or prohibitive cost of customary fuel such as coke or charcoal, will be greatly facilitated.

It is the object of my invention to permit the use of non-porous fuels, by treatin the burden comprising the ore and flux or uxes in such a manner as to produce therein a porous structure. This I accomplish by properly crushing the burden-constituents, either in whole or in part, mixing the same to a homogeneous mass, and thereafter sintering the same to produce a porous product.

The sintered product is then mixed with sufficient fuel to effect its reduction and the mixture char ed to the blast furnace. Dependin on t e structure of the sinter and the fue it may be necessary to crush either or both before mixing and charging to the blast furnace, or the mixing of the .sinter and fuel may be eliminated and each charged alternately to the furnace. The use of a sintered product having a porous structure gives the additional advantage that a sinter is produced that Wlll. pocket or occlude any finely divided fuel which may be possible a Application filed larch 7, 1921. Serial No. 450,424.

used for reducing purposes. The sinterin of thepre and flux either with or withouli preliminary crushing, results in a product whichby its structure and analysis makes considerbale fuel economy whether coke, charcoal or other fuel is employed.

A specific example of my invention applied to the treatment of iron ores is as follows: The iron ore is preferably crushed to the required fineness and suitable flux or fluxes of requisite fineness added thereto, the lngredients being intimately mixed to a homogeneous mixture. The latter is then s ntered to produce a porous mass of sufiiclent strength to withstand the pressure of superimposed successive charges fed to the furnace. The sintered material is thereafter, with or without crushing, preferably mixed with the fuel to insure proper contact of the fuel with the material to be reduced. This last mixing step may be dispensed with if desired, and the sintered product and fuel charged successively to the furnace.

The process, as broadly outlined, admit; of many modifications, so 10 as the essential condition that enough sinter of iron ore and flux or fluxes be used to ive the necessary porosity to the charge an permit the utihzation of fuels other than porous ones such as coke or charcoal now in general use.

This process makes possible the use of non-coking coals which may be treated in a retort similar to coke manufacture, the volatile constituents being driven off. The resulting product is essentially a coke of poor structure and strength, but may be used with sinter on account of the porosity and strength supplied by the latter. So, too, woods and wood products which are not now used for the making of charcoal, but which could be made into charcoal of an inferior uality and used'with my sinter 01' used wit out previous treatment, withouthaving been turned into charcoal before use, may be employed.

The process may be varied so as to permit the use of a mixture of sintered and unsintered burden.

The production of a sintered product permits the use of substantially any form of carbonaceous ma rial, for example, coals, both coking an non-coking, ligmte,

peal. sawdust, charcoal, residues of oil or other distillation processes, fuel oils, or powdered or gaseous fuels.

The terms burden and charge are to be given their customary significance. The burden consists of the ore and flux, being the amount of material that the fuel has to melt. The charge includes both the burden and the fuel.

\Vhat is claimed is,

1. The process of treating iron ores C0111- prising sintering the burden to produce a porous structure therein, adding a nonporous fuel thereto and smelting the charge to recover the iron-content.

2. The process of smelting iron ores which comprises sintering a portion at least of the burden to produce a porous structure therein, adding a fuel thereto normally incapable by reason of its physical structure of being used as a fuel medium in the process of smelting, and finally smelting the charge. i

3. The process of smelting iron ores which comprises mixing the same with a flux or fluxes, sintering the mixture to produce a porous structure therein, adding a 7 fuel thereto normally incapable by reason of its physical structure of hem used as a fuel medium in the process of smeltering, and finally smelting the charge.

In testimony whereof I have signed my name to this specification.

WILLIAM R. VAN SLYKE. 

